OTTAWA — Canada’s ethics watchdog has launched an investigation into allegations that the Prime Minister’s Office pressured former attorney general Jody Wilson-Raybould to help construction giant SNC-Lavalin avoid criminal prosecution, even as Prime Minister Justin Trudeau says he told Wilson-Raybould personally last fall that the decision was hers to make.

Ethics commissioner Mario Dion confirmed his investigation Monday in a letter to NDP MPs Charlie Angus and Nathan Cullen, who raised possible violations of the Conflict of Interest Act.

In the letter, Dion said he has “reason to believe that a possible contravention of section 9 (of the act) may have occurred.” That section prohibits public office holders from trying to influence decisions that could “improperly further another person’s private interests.”

Speaking to reporters at a housing announcement in Vancouver, Trudeau said he welcomes the investigation, as “it’s extremely important that Canadians can continue to have confidence in our system.”

He said he had met twice with Wilson-Raybould, who represents a downtown Vancouver riding, since he arrived in the city on Sunday, though she was not present with him at the announcement. He said he still has “full confidence in Jody,” and said she acknowledged that he had affirmed her independence as attorney general in a meeting months ago.

“We spoke about our shared goals for our country and for this government,” he said. “She confirmed for me a conversation we had this fall where I told her directly that any decisions on matters involving the director of public prosecutions were hers alone.”

A Globe and Mail report last week cited unnamed sources who said the Prime Minister’s Office pushed Wilson-Raybould to direct federal prosecutors to negotiate a deal with SNC-Lavalin that would have led to a fine instead of a criminal trial.

The Quebec company was charged in 2015 with bribing Libyan officials between 2001 and 2011 in exchange for construction contracts.

The Post has not independently confirmed the allegations of political interference.

Wilson-Raybould, who was shuffled out of the justice portfolio last month, has said little publicly about the allegations, citing solicitor-client privilege. On Sunday, Conservative Leader Andrew Scheer wrote to Trudeau to demand that he waive that privilege and allow Wilson-Raybould to speak openly.

But Trudeau said that the question of waiving privilege “is not a simple one.” He said he’s asked current Attorney General David Lametti to provide him with recommendations.

In Ottawa, Lametti gave a speech Monday at a Canadian Bar Association conference during which he pointed to his dual role as a member of cabinet who deals with justice policy and as the government’s main legal adviser who oversees the public prosecution service. “It is important to remember that while the attorney general sits at a certain distance from his cabinet colleagues, in Canada, unlike in other countries, he does not work in isolation from them,” he said. “But there is a line that cannot be crossed. Telling the attorney general what a decision ought to be: that would be interference.”

Lametti later refused to answer several questions from reporters, saying that it would be inappropriate to comment as attorney general, since the SNC-Lavalin case is before the courts.

The ethics investigation comes as the House of Commons justice committee prepares to hold an emergency meeting on Wednesday to debate a motion calling for Wilson-Raybould and several senior officials in the PMO to testify about the allegations of political interference. Over the weekend, the Toronto Star reported that the majority-Liberal committee is likely to block the opposition’s attempt to call witnesses. In response, committee chair and Liberal MP Anthony Housefather tweeted that he will “independently determine” whether a committee study of the issue is necessary. “Nobody has attempted to influence me,” he wrote.

Speaking to reporters in Fredericton on Monday, Scheer said the Liberals must allow the committee to proceed, regardless of the ethics investigation. “If Justin Trudeau decides to stonewall us or to shut down the committee on Wednesday, we will use every legal and law enforcement tool at our disposal,” he said.

This is incorrect @TondaMacC. I am closely following all info and convening a Justice meeting Wed related to SNC. I intend to independently determine whether Committee study of the issue will be useful for Canadians & colleagues will do same. Nobody has attempted to influence me. https://t.co/b0S8huE3WU

Earlier on Monday, Wayne Long, a backbench Liberal MP from New Brunswick, broke ranks and joined the Conservatives and New Democrats in calling for the justice committee to investigate. “I also am seeking answers that will clear the air regarding exactly what happened here, and, because I was raised to believe that full transparency is always the best approach to addressing such uncertainty, I believe that a full and transparent investigation is necessary to ensure that my constituents, and all Canadians, can be confident in (the) veracity of those answers,” he said.

The Liberals have insisted that they did not pressure Wilson-Raybould to make a deal with SNC-Lavalin, known as a deferred prosecution agreement. Last week, Trudeau told reporters that the allegations were false. “At no time did I or my office direct the current or previous attorney-general to make any particular decision in this matter,” he said.

On Sunday, Lametti told CTV’s Question Period it’s still possible he could direct the prosecution service to make a deal with SNC-Lavalin to avoid a criminal trial, but said he wouldn’t comment further as the case is before the courts. The attorney general can issue directives to federal prosecutors, but the directives must be published in the Canada Gazette, the federal registrar.

In October, the director of the public prosecution service told SNC-Lavalin it would be inappropriate to negotiate a deferred prosecution agreement. The company has asked for a judicial review of that decision. If SNC-Lavalin is convicted in a criminal trial, it could be barred from government contracts in Canada for 10 years.

The Liberals introduced deferred prosecution agreements in the last budget bill. Similar measures already exist in the U.S. and the U.K.